title: Conservation analysis of class-specific positions in cytochrome P450 monooxygenases: functional and structural relevance.
abstract: Cytochrome P450 monooxygenases (CYPs) constitute a ubiquitous, highly divergent protein family. Nevertheless, all CYPs share a common fold and conserved catalytic machinery. Based on the electron donor system, 10 classes of CYPs have been described, but most CYPs are members of class I accepting electrons from ferredoxin which is being reduced by FAD-containing reductase, or class II accepting electrons from FAD- and FMN-containing CPR-type reductase. Because of the low sequence conservation inside the two classes, the conserved class-specific positions are expected to be involved in aspects of electron transfer that are specific to the two types of reductases. In this work we present results from a conservation analysis of 16,732 CYP sequences derived from an updated version of the Cytochrome P450 Engineering Database (CYPED), using two class-specific numbering schemes. While no position was conserved on the distal, substrate-binding surface of the CYPs, several class-specific residues were found on the proximal, reductase-interacting surface; two class I-specific residues that were negatively charged, and three class II-specific residues that were aromatic or charged. The class-specific conservation of glycine and proline residues in the cysteine pocket indicates that there are class-specific differences in the flexibility of this element. Four heme-interacting arginines were conserved differently in each class, and a class-specific substitution of a heme-interacting tyrosine by histidine was found, pointing to a link between heme stabilization and the reductase type.
authors.affiliation: Institute of Technical Biochemistry, University of Stuttgart, 70569, Stuttgart, Germany.
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Gricman
authors.forename: Constantin
authors.initials: C
authors.lastname: Vogel
authors.forename: Jürgen
authors.initials: J
authors.lastname: Pleiss
mesh_terms: D000596:Amino Acids; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry* / Q000378:metabolism; D030562:Databases, Protein; D006418:Heme / Q000737:chemistry / Q000378:metabolism; D006860:Hydrogen Bonding; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D011487:Protein Conformation
chemical_list: D000596:Amino Acids; D006418:Heme; D003577:Cytochrome P-450 Enzyme System
keywords: CYP; P450; conservation; database; heme interaction; reductase interaction site; sequence-structure-function relationship